In a newly assembled internal combustion engine wherein there is employed an oil filter with an anti-drainback valve, the latter can in some installations block filling or priming of the lubrication system between the engine oil pump and the filter and between the filter and the main oil gallery and, in particular, the hydraulic tappets. As a result, on initial engine startup and without full priming or filling, there can result discernible noise until the hydraulic tappets are filled or pumped up. For this reason, it has previously been proposed to provide a special fill connection between the pump and filter and also between the filter and the hydraulic tappets and also to pre-charge the filter prior to its assembly. The former provisions require additional space and cost, and the latter provision requires a separate filling operation and is prone to spillage, particularly where the filter as installed has its example, where the filter is mounted horizontally, it is prone to spill from the filter if pre-charging is attempted prior to assembling the filter on the engine. Furthermore, these manners of filling are to be distinguished from the far more costly pre-tart engine lubrication systems that charge an engine's lubrication system prior to every start or on a selective basis.